Mechanical Engineering Technology

Team #1 3D Metal Printing

Introducing the Team

Team 01 consists of 3 senior members of the Mechanical Engineering Technology 2020-2021 class.

Zachary Epstein is from Madawaska, Maine.  Zack has worked multiple jobs throughout his young career, from doing lawn maintenance to working construction to working in a restaurant to most recently working for General Dynamics Mission Systems in Pittsfield, Massachusetts.  Zack is a 4th year senior and is looking to continue full time at GDMS after he graduates.

Ashton lord is from Dayton, Maine.  He started his work in the world of manufacturing as a junior in high school where he attended a vocational program for precision machining.  He later went on to graduate from Southern Maine Community College with an associate degree in precision machining.  This all the while working at an aerospace machine and manufacturing facility called Arundel Machine Tool.  Now back in school to further his education as fourth year MET student.

Jacob B. Smith is a senior student at the University of Maine, majoring in Mechanical Engineering Technology and minoring in Electrical Engineering Technology. An inventor at heart, Jacob choose his educational path to best suit his desire to imagine, create, and build a better world around him while equipping him with the knowledge and resources to fully realize these goals.

Project Description

The 3D Metal Printed Stirling engine is a project given to the MET department by John Belding the Co-Director for the Center for Additive Manufacturing of Metals (CAMM). Mr. Belding wants a desk size Stirling engine that can be used for job fairs and visits to show the capabilities of additive manufacturing.  The engine would be created using the Desktop Metal Studio System which prints with either 316L or 17-4 PH steel.  By using bound metal deposition (BMD) the rods are mixed with the steel and wax and other materials and then printed to the required shape.  Once printed the parts are then put through the sintering process in which removes a majority of the wax and other materials leaving only the steel.  Once it is done in the sintering process, it is put into the furnace to strengthen the steel.

IR1 Overview

IR1 was the team’s first major step in this project.  The project is now on it’s 3rd iteration.  Mr. Belding originally gave this project for the 2018-2019 school year.  That year’s team was unable to create a functioning prototype, instead they eliminated that an beta style Stirling Engine would not work.  The 2nd iteration of this project the 2019-2020 school year’s group got much closer.  The team was able to produce an alpha style Stirling Engine and another beta style Stirling engine, but neither of those designs worked.  The team then created a gamma style Stirling Engine and that decided passed the plastic prototype stage.  They attempted to print their gamma style engine but due to the pandemic, this team was unable to complete their metal prototype.

This year’s team is picking up where last year’s team failed.  By modeling their prototype using plastic 3D printing and then printing using the Studio System to have a functioning prototype.

Weekly Updates

11/23/2020

The ordered Stirling engine kit has arrived and been tested. the team will be taking steps to integrate the glass cylinders from this model into a retrofit design for the polymer printed model. The polymer model is nearly finished printing, and the team expects to have an assembled model by the end of this week.

11/30/2020

The team will be looking into the effects of sintering metal to determine changes in the designed model.

The polymer parts are nearly finished, with a delay due to a team member having to quarantine due to potential virus exposure.

                  

Flywheel            Counter-weight       Power Cylinder

 

12/07/2020

The Polymer model engine is nearly finished at more than half assembled. The team used the week to focus on creating and editing the IR2 document, with most of the document already finished.

01/29/2021

Team 1 has gotten off to a quick start for the Spring Semester.  During Winter break, Isopropyl alcohol, wicks and mini candles were ordered to act as fuel sources for the Stirling engine.  The team is currently working towards a February 1, 2021 deadline of a revised IR2, Team Deadline, and Client Contract.  The teams current goal is once they have received feedback on the IR2 revisions to start printing the PLA prototype and have that assembled by February 15, 2021.

02/07/2021

The team met deliverables for the revised IR2, client contract and team contract.  The goal for this coming 2/08/2021 is for all of the PLA parts to be printed.  Currently all but 3 parts have been printed and the remaining parts will be printed late Sunday Night into Monday Afternoon.  Overall, the team is on track.

02/14/2021

No huge update, parts have been printed.  Attempted to assemble the PLA prototype, many PLA parts broke during assembly, needed to be reprinted.

2/21/2021

Team has fallen slightly behind schedule, many more issues occurred during the assembly process, the scale of multiple parts were off by a factor of 5%.  Team has started the reprinting of these parts in order to correctly have the right scale.

02/28/2021

Team has fallen behind further, the assembly process has proven more rigorous than intended, we have been having trouble making the fit correctly.  A major breakthrough with the base plate was made however.  The cracking issue has mainly been solved by the team.  We have concluded that with the masses on each side, the middle supporting beam is to small in order to compensate the frictional, force, and pressure build up during the cooling process in which the part is shrunk by approximately 20%.

03/07/2021

The team is currently in process of making the IR3 design package for review.  Due to some unforeseen circumstances the team is slightly behind with the initial due date of 03/08/2021.  The assembly of the PLA prototype is stalled currently to the tight clearance needed to achieve a proper pressurization.

05/03/2021

After design iterations and failed testing of the PLA prototype, the team speculated the polymer design was not running due to lack of mass in the flywheel and not enough heat in the cylinder due to the PLA parts melting rapidly. From this hypothesis the team was granted to move forward with printing the new design in metal.  The parts were successful in printing and sintering with no cracking to be found. The parts were 3d scanned and tested against the cad models and found to have minimal distortion. The parts were finished to assembly spec via machine tools such as a lathe, milling machine, and hand tools such as files and a deburring tool.

The fully assembled 2020 engine design was then tested and shown to run under its own power.  The finished 3d metal printed stirling engine can be seen below.

 

The 2020 team was successful in their endeavor’s to fulfill the task given by the center for additive metal manufacturing, and would like to thank everyone involved in this project for the work they did to see it to completion.